Using method of safety protection of high-voltage and direct current contactors for electric automobile

Abstract

The invention discloses a using method of safety protection of a high-voltage and direct current contactors for an electric automobile. The using method comprises the steps that at the time of precharging a motor controller, specifically, a main negative contractor is closed when high voltage power-on of an electric automobile direct current high voltage system is conducted, then a precharging loop is closed to finish precharging of the motor controller, and finally a main positive contractor in the electric automobile direct current high voltage system is closed; and partition current flow direction outage is adopted at the time of the outage of the electric automobile direct current high voltage system. The specific process comprises the steps that if the current flow direction in the system is consistent with the current flow direction when precharging is conducted on the motor controller, the main positive contractor is switched off firstly and then the main negative contractor is switched off; and if the current flow direction in the system is opposite to the current flow direction when precharging is conducted on the motor controller, the main negative contractor is switched off firstly and then the main positive contractor is switched off. In the process of charging and discharging of the high voltage system, the effect of protecting the contact points of the high voltage contractors is achieved by controlling different closing orders of the main positive and negative contractors.

Description

technical field [0001] The invention relates to a direct-current high-voltage system of an electric vehicle, and in particular to a method for using a safety protection DC high-voltage contactor of an electric vehicle. Background technique [0002] In recent years, electric vehicles have become more and more common as a new means of transportation. The popularity of electric vehicles has continued to increase, and the technologies involved in the development and manufacture of electric vehicles have also continued to improve. The high-voltage main contactor of electric vehicles is an important part of the high-voltage circuit of electric vehicles. The high-voltage system of the battery pack of electric vehicles can only output high-voltage power to external electrical appliances by closing the high-voltage main contactor. The number of closing times of the high-voltage main contactor is limited, especially when the high-voltage circuit has a current flowing through it, it wi...

AI Technical Summary

Problems solved by technology

[0003] The safety protection method of high-voltage DC contactors for electric vehicles often only considers the method of using the high-voltage contactor in the forward direction, which is reasonable when it is turned on. The contacts of the contactor are damaged, which seriously affects the service life of the contactor

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